Drilling platform with corresponding supply vessel

ABSTRACT

A marine drilling platform is recessed at one side to receive one end of a supply vessel in pushing or pulling relationship. Both the platform and the vessel have power sources comprising motors, but only the supply vessel has propulsion means. The power from both the platform power source and the supply vessel power source is applied to the propulsion means of the supply vessel, thereby taking advantage of the power which must in any event be provided on the drilling platform for drilling operations and the like.

United StatesPatent r1191 Peereboom 1 DRILLING PLATFORM wmr CORRESPONDING SUPPLY VESSEL [75] Inventor:

[73] Assignee: N. V. Industrieele Handelscombinatie, Rotterdam, Netherlands 22 Filed: Feb. 9, 1973 211 Appl. No.2 331,175

[30] Foreign Application Priority Data Feb. 10, 1972 Netherlands 7201761 [52] US. Cl 114/235 R, 114/.5 D, 114/435, 290/1 R [51 1 Int. Cl B63b 35/44 [58] Field of Search 1 14/235 R, 236, 43.5, .5 D; 115/6; 290/1 R;l05 /62 B,- 98 9 9 [56] References Cited UNITED STATES PATENTS 1,014,313 1/1912 M acklind ..l15/6 1 l llss Hans Peereboom, Delft, Netherlands 1111 3, 15,540 June 11, 1974 2,039,399 5/1936 Englis 114/435 3,271,964 9/1966 114/.5 D 3,442,239 5/1969 Wilson 114/.5 D 3,483,842 12/1969 Ohcho et al. 114/235 R Primary Examiner-George E. A. Halvosa Assistant ExaminerEdward R. Kazenske Attorney, Agent, or FirmYoung & Thompson l 5 7 l ABSTRACT 4 Claims, 4 Drawing Figures DRILLING PLATFORM WITH CORRESPONDING SUPPLY VESSEL The present invention relates to a drilling platform or similar movable installation with a corresponding supply vessel, whichis simultaneously adapted to propel the drilling platform or the movable installation to the form is towed by one or more tugs with the aid of long tow-ropes or hawsers. With the other method the drilling platform itself is equipped with propellers and navigational equipment, so that tugs have become superfluous.

The drilling platform is generally provided with its own power for drilling, raising, and similar purposes, which is generally on the order of magnitude of 4,000 hp. The power required for the propulsion of a self propelled drilling platform, or adrilling platform propelled with the aid of one-ormore tugs is generally about 8,000 h.p.

With the first-mentioned method the power required for towing the drilling platform is simply generated by choosing the appropriate number of tugs. The acquisition of tugs generally does not present any problems, while furthermore this method does not require any expensive provisions, however, a great disadvantage of this method is that transportation is slow and therefore expensive due tothe unfavourable shape of the drilling platform to be towed, this causes a high resistance to be produced, which slows down the speed of the transport. A further disadvantage is the fact that the drilling platform is practically left to the mercy of the sea in case the hawser's get broken, in a storm for instance, when it can be a most difficult job to renew the contact. A further disadvantage is the possibility that towing a drilling platform is a new experience to the crew of a tug. Ignorance and inexperience where towing drilling platforms is concerned may lead to further errors and delays. Furthermore manoeuvring a drilling platform being towed is a'relatively complicated procedure.

' The second method, i.e. the method in which the drilling platform is self-propelled, requires additional power to be installed inthe drillingplatform, more particularly for the propulsion and displacement of the same. In addition to said disadvantage with this method the shape and lay-out of the drilling platfonn have to be adapted to the location of the propellers and the driving gear. Moreover the drilling platform will generally have to be given a reasonably stream-lined shape in order to be able to move at a fair and yet safe speed. A further disadvantage is that the drilling platform must be provided with navigational apparatuses, additional crew, additional accommodation, etc. Although this method makes one independent .of third parties,

since the driving gear is present under allconditions, the considerable first cost and cost of operation of such a self-propelled drilling platform due to the propulsion, navigational means, and the like, are a great disadvantage.

An added expense is that a drilling platform generally needs a supply vessel, said vessel carryingthe required stores, food, mud, drills, etc. The power installed in a 4,000 hp. With the towing method the supply vessel can simply serve as one of the tugs. In practice the supply vessel is not used as the only tug, inasmuch as such a vessel has not got the capacity for towing the drilling platform at a safe speed, for instance, in case of a storm, tides, and'the like. With the second method the drilling platform is not only self-propelled but needs a supply vessel as well, this makes this method even more expensive when compared with the towing method.

The object of the present invention is to eliminate the disadvantages of both the aforementioned methods and to provide a better method for displacing a drilling platform. To this end the drilling platform and the supply vessel are provided with a source of energy comprising supply vessel is generally on the order of magnitude of an engine and generator or pump, while the supply vessel is simultaneously provided with a driving propeller with driving motor, which is connected with the generator and pump of the vessel respectively, whereby the driving motor(s') of the propeller(s) of the supply vessel is (are) suited to receive simultaneously the full power of both the generator or pump of the supply vessel and the generator or pump of the platform, means having beenprovidedin order to connectvessel with platform in propelling or towing connection, and means to conmeet the generator or pump of the platform with a propeller driving engine of the supply vessel in said connected condition.

Therefore the presentinvention provides a method for displacing a drilling'platform withthe aid of one vessel, and this the supply vessel, whereby the drilling platform can be propelled to its destination at a satisfactory and safe speed by making use for the propulsion of said drilling platform of the source of energy present on the drilling platform as well as of the source of energy present on the vessel itself. A supply vessel having a power of about 4,000 hp. of its own plus a power of about 4,000 hp. originating from the drilling platform cessed portion. In an alternative embodiment of the invention the rear portion of the vessel is connected with the drilling platform in said recessed portion. In this embodiment the disadvantage is that the propeller(s) of the vessel are between the vessel and the drilling platform, so that a satisfactory propeller action and propeller flow are interfered with. In order to increase the useful effect of the propulsion additional provisions are required, such as additional propellers and driving motors in the bow portion of the vessel. If the additional propellers are reversible cycloid propellers the vessel can either tow the drilling platform or push it.

The combined drilling platform-vessel according to the present invention has more particularly advantages from an economic point of view with respect to the conventional methods for the displacement of a drilling platform, i.e. towing and self-propulsion.

When compared with the towing method the initial costs will be higher on account of the required provisions on the vessel and the drilling platform according to the invention, but the cost of transport will be considerably lower because the conventional towing operation with a number of tugs is a time-comsuming and expensive procedure. The economic advantage is even greater with respect to a self-propelled drilling platform. The initial costs of such a platform, increased by the cost of a conventional vessel for the supplies, are considerably higher than those of the installation according to the invention. Furthermore the operational costs are higher on account of the numerous provisions required on such a drilling platform with a propulsion of its own, such as propellers, additional engines, navigational means, additional crew, and the like.

As additional advantages may be mentioned: Optimal use of the supply vessel, the constant presence of propellers for the drilling platform, no tugs required, the displacement of the drilling platform being carried out the recessed portion and is substantially rigidly connected with the drilling platform 1 by means of removable members 6, for instance, in the form of clamps and supporting means. For convenience sake the drilling by an experienced crew of the supply vessel, improved manoeuvrability, and a greater safety due to the substantially firm connection of the vessel with the drilling platform, because with the towing method the breaking of the hawsers and re-establishing the connection with the platform is a hazardous procedure during a storm.

It is generally possible to adapt supply vessels already in existence to drilling platforms already in existence, since a drilling platform is generally provided with a recessed portion, which can be made suitable for the accommodation and connection of a vessel in a simple manner. Relatively few provisions have to be made: For the supply vessel a more powerful engineand propeller( s), and connecting means, and for the drilling platform connecting means to connect the platform with the vessel, for instance clamping and supporting ele ments for the-vessel. When drilling platforms and supply vessels are to be newly built, it is to be understood that the provisions described above can be adapted to one another in the most favourable manner.

Embodiments of the invention will now be explained in more detail with reference to the annexed drawings, wherein: FIG. 1 is a top view of a drilling platform with a pushing supply vessel according to a preferred embodiment of the invention;

FIG. 2 is a side view of the drilling platform with vessel of FIG. 1 on an enlarged scale;

FIG. 3 is a top view of a drilling platform with a towing supply vessel according to an alternative embodiment of the invention;

FIG. 4 is a side view, on an enlarged scale, of the drilling platform with vessel of FIG. 3. l

FIG. 1 shows a drilling platform I with four columns (la, lb, 1c and 1d) and a slight stream-lined shape at the front in front of the columns la and lb. The drilling platform I has been provided with a diesel engine 2 with a coupled generator 3, which is adapted to provide the required energy, for instance, for raising and drilling. Every drilling platform is generally provided with such a diesel engine-generator combination, so that these provisions are not a novelty. At the rear portion of the drilling platform I is provided a recessed portion 4. Drilling through this recessed portion is a normal procedure. A pushing vessel 5 fits with its front portion in the recessed portion 4 of the drilling platform 1. In FIGS. 1 and 2 the situation is shown in which the pushing vessel 5 is accommodated with its front portion in platform is not shown in its entirety in FIG. 2. For the sake of clarity the starboard rear portion of the drilling platform, abutting the recessed portion 4, has not been shown either, so that the pushing vessel 5 with clamps and supporting members 6 in the recessed portion 4 is clearly visible. The pushing vessel 5 is provided with a diesel engine 7 with a coupled generator 8. The generator 8 is connected with one or more electric motors 9, which are adapted to energize adjustable propeller or propellers 10. If the pushing vessel 5 is connected with the drilling platform 1, as is shown in the drawing, a connection can be made in a cable 11 between the generator 3 of the drilling platform 1 and the electric motor(s) 9 of the pushing vessel 5. The electric motor(s) 9 has (have) a sufficiently large capacity to take up both the full power of 'the generator 3 of the drilling platform 1, for instance, 4,000 hp, and the power of v the generator 8 of the'pushing vessel 5 itself, for instance, 4,000 hp. and to transfer the combined power to the propellers 10.

In the coupled conditions, as shown in'FlGS. 1 and 2, the power of the generator 3 of the drilling platform 1 is transferred through the cable 11 to the pushing vessel 5 and is there taken up and used by the electric motor(s) 9 to which also they power of its own generator 8 is transferred. The electric motor(s)- 9 transfer the combined power to the propellers 10 with the result that the pushing vessel 5 has a sufficient total capacity to propel the drilling platform 1 with a fair, safe speed to be disconnected, for instance, to serve as supply vessel, the cable 11 is interrupted by detaching a connecting piece in said cable which may be fitted in any chosen spot in said cable 11. Subsequently the removable connecting means 6 are taken away, so that it is possible for the vessel 5 to sail away from the recessed portion 4 of the drilling platform. When the pushing vessel is in normal use, i.e. in its capacity as supply vessel without drilling platform, the drive means 9 is fed only by the generator 8 of the vessel 5 itself, which is sufficient for normal use.

In FIGS. 3 and 4 an alternative embodiment of the invention is shown. In this embodiment the stern of the supply vessel is in the recessed portion of the drilling platform and connected with the drilling platform. Like elements are denoted by like reference numerals, as in FIGS. 1 and 2. During normal operation of the supply vessel 5 without the drilling platform the diesel engine 7, generator 8, driving motor(s) l2 and propeller(s) 13 are activated. The supply vessel 5 is provided with an additional drivingmotor 9 with additional propeller(s) 10 (see FIG. 4) in the front portion of the vessel. When the vessel 5 is towing the drilling platform 1 the generators 3 and 8 supply their energy to the driving motor(s) 9 for driving the propellers 10. This embodiment is also suited to push instead of to tow the drilling platform. In that case the vessel 5 sails backwards. If the propellers 10 are reversible propellers, it is possible either to push or to tow the drilling platform in the coupled condition, as is shown in FIGS. 3 and 4.

It will be apparent that various alterations are possible. The supply vessel 5 may, for instance, be condevices than the connecting members 6 and in a different manner. The'propellers of the vessel may be cycloid propellers. The system to transfer the energy from drilling platform to vessel may be a hydraulic system, in which the system comprises pumps and hydromotors instead of generators and electric motors. it is possible to provide the supply vessel with a second motor which is connectable by means of a propeller shaft and can only be taken up in the circuit of the generator or pump of the drilling platform.

I claim:

1'. The combination of a drilling platform and a supply vessel, the drilling platform having a power source thereon, the supply vessel having a power source thereon and propulsion means for conjointly propelling the supply vessel and platform, means releasably interconnecting the supply vessel and platform, and means for supplying to said propulsion means power simultanected with the drilling platform 1 by means of other .6 neously from said power source of said supply vessel and from said power source of said platform.

2. Apparatus as claimed in claim 1, one side of said drilling platfonn having a recess through which drilling operations are conducted in the absence of said supply vessel, said interconnecting means releasably connecting one end of said supply vessel in said recess to said platform.

3. Apparatus as claimed in claim 2, said supply vessel having a bow and a stern and having propulsion means at the bow thereof and having the stern in said recess.

sion means of said supply vessel.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIQN Patent No. 8 Dated n 1974 Hans Peereboom Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Change the name of the assignee to N. V. Industrieele Haride lscomb'irlatie Holland v signed iarid sealed this 14th day of January 1975.

- (SEAL) Y I 1 Attest:

McCOY M GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents FORM USCOMM-DC nous-p09 u. s. sovnnnzu-r rnm'nus orncz: 8 69 93 o Patent No. Dated June" 11, 1974 Hans Peereboom Inventor-(s) It is certified that error appears in the above-idefitified patent and that said Letters Patent are hereby corrected as shown below:

Change the name of the assignee to N. V. Industrieele Handelscomb'inatie Holland Signed-arid sealed this 14th day of January 1975.

- (SEAL) Attest:

McCOY M GIBSON JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents FORM -PO-HJ5O I v uscoMM-Dc 60376-P69 11.5, GOVERkMENT PRINIYNG OF ICE: 9 930 

1. The combination of a drilling platform and a supply vessel, the drilling platform having a power source thereon, the supply vessel having a power source thereon and propulsion means for conjOintly propelling the supply vessel and platform, means releasably interconnecting the supply vessel and platform, and means for supplying to said propulsion means power simultaneously from said power source of said supply vessel and from said power source of said platform.
 2. Apparatus as claimed in claim 1, one side of said drilling platform having a recess through which drilling operations are conducted in the absence of said supply vessel, said interconnecting means releasably connecting one end of said supply vessel in said recess to said platform.
 3. Apparatus as claimed in claim 2, said supply vessel having a bow and a stern and having propulsion means at the bow thereof and having the stern in said recess.
 4. Apparatus as claimed in claim 3, said supply vessel having propulsion means both in said bow and in said stern, and means for selectively directing power from at least one said power source to each of said propulsion means of said supply vessel. 